Numerical Modelling of Two Tier Spillway

Spillway flows are classical problem of gravity driven free surface flow hydraulics. These flows are very complex because they are highly turbulent and unsteady involving two phases (air& water) with a large density difference. These features pose a unique challenge to simulate these flows numerically. The two tier spillway in a combination of two spillways, an overflow spillway and a sluice spillway at bottom. A study was completed to compute flow parameters over a two tier spillway using a 2-D numerical model. Water surface profile, discharge and pressure data were recorded for different flow conditions. A commercially available computational fluid dynamics (CFD) program, which solves the Reynolds-averaged Navier-Stokes equations, was used to model the two tier spillway. The results were compared with available experimental data from 155 scale 2-D sectional physical model to assess the accuracy of numerical results and found in good agreement.